Pipe joint mechanism having high maintainability with wrap-around seal member

ABSTRACT

This invention relates to a joint mechanism of pipes having high maintainability for a pipeline disposed in a building or a buried object. An insertion member is interposed between the pipes or between the pipe and equipment to be connected and packing is applied over these three members. The packing is set and clamped by meshing of two screwed clamping rings.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a pipe joint mechanism for improved connectionof branch pipes to, and fitting or replacement of valves and otherequipment in a pipeline disposed in a building or in a soil layer, andis directed to provide a joint which facilitates and simplifies workrequired when part of an existing pipeline is connected to another pipefor partial repair or the like or when a valve, a meter or a flange isfitted to the pipeline or replaced.

2. Description of Related Art

Various joints have been proposed and put to practical use in the pastwhich have been employed for partial improvement to, connection ofbranch pipe to and fitting or replacement of equipment such as a valvein a pipeline. Typical examples of such conventional joints employed forsuch purposes are illustrated in FIGS. 8 through 11 of the accompanyingdrawings.

In the joint shown in FIG. 8, a packing 22 is interposed between jointmembers 20 and 20 each having a screw portion 21 for meshing with a mainpipe that forms a pipeline and a connecting ring 23 is anchored to astep portion 24 of one of the members 20 and is meshed at 25 with theother member 20.

In the joint shown in FIG. 9, ring-like grooves 32, 32 engaging with aring chip 29 and a fitting confirmation line 33 are formed on a mainpipe 26, a ring packing 31, a movable ring 30 and the ring chip 29 aresandwiched between a nut 28 engaging with a female screw portion of amain body 27 and the main body 27. The insertion depth of the main pipe26 is determined by the fitting confirmation line 33, the nut 28 isscrewed in while the ring chip 29 and the ring-like grooves 32, 32 arebeing aligned to one another, the main pipe 26 is clamped and restrictedby the ring chip 29 and seal is effected by the ring packing 31.

In the joint showing in FIG. 10, nut members 36, 36 are each fitted toeither side of an intermediate member 35, a main pipe is inserted up tostep portion 37, 37 formed in the intermediate member 35 and after apacking is interposed, each nut member 36 is screwed so as to attain aseal on the outer surface of the main pipe by the packing.

In the joint shown in FIG. 11, a nut member 43 is set over two jointmembers 42, 42 interposing a seal member 41 such as an O-ring betweentheir joint surface or in other words, the nut member 43 is anchored toan anchor step 45 formed on one (42) of the joint members and screwed tothe other joint member 42. The main pipe to be connected is insertedinto a fitting portion 44 in both joint members 42 and is welded aroundits entire periphery at the end portions 46 of the joint members 42.

In the conventional joints such as described above, however, theirconnecting works or operations are complicated and man-hours inevitablygreat.

In the joint shown in FIG. 8, a male screw must be threaded on the mainpipe to be connected in order to screw-fit the joint member 20 to thescrew portion 21 and in order to form such a male screw, the main pipewhich has been laid down and kept under fixed state must be taken outover a considerable length or must be arranged so that a threading toolcan be fitted to it and operated before the male screw is threaded. Thismeans that a wall or soil layer must be broken to take out the main pipeor to establish the state where the threading tool can be fitted andoperated, and the extent of the subsequent repair becomes essentiallyvery great. Accordingly, many man-hours and quantities of materials arerequired for the repair.

In the joint shown in FIG. 9, too, the main pipe 26 must be taken outover a considerably great length so as to form the ring-like grooves 32,32 meshing with the ring chip 29 and the fitting confirmation line 33.Therefore, the wall or soil layer must be broken over a considerablygreat range to take out the main pipe and the pipeline must then berepaired in the same way as the joint shown in FIG. 8.

In the joint shown in FIG. 10, a small diameter portion 38 which is inalignment with the inner diameter of the main pipe must be formed at thecenter portion of the intermediate member 35 so as to make the flow of afluid from the main pipe smooth. Therefore, even if the end portion ofone of the main pipes can be inserted by sliding the intermediate member35, the other pipe cannot be inserted up to the step portion 37 becausethat main pipe is kept under the fixed state. Therefore, a large-scalemoving operation is necessary for at least the other main pipe and manyman-hours are inevitably required.

Since the joint shown in FIG. 11 includes two joint members 42, fixingby welding must be carried out carefully to assure water-tightnessbetween these two joint members 42, 42 and the main pipe, respectively.Therefore, a space sufficient enough to operate a welding rod around theentire periphery of each portion and many man-hours are inevitablyrequired.

SUMMARY OF THE INVENTION

The present invention provides a joint mechanisms of pipes characterizedin that an insertion member having an outer diameter greater than thatof a main pipe or a tubular portion of equipment or a branch pipe isdisposed between the main pipe and a new pipe to be connected or betweenthe main pipe and said tubular portion or main pipe to be connected, apacking is applied over the insertion member and the main pipe or thetubular portion, and a first clamping ring having a male screw formedthereon and a second clamping ring engaging with a nut member having afemale screw meshing with the male screw are set over and clamp thepacking.

In the present invention, the insertion member between the main pipe andthe tubular portion or the main pipe is interposed under the conditionwhere the main pipe(s) or the tubular portion is kept fixed.

After the packing is applied over the main pipe, the insertion memberand the tubular portion or a main pipe, the nut member anchored to thesecond clamping ring is engaged with the first clamping ring so as tofasten and suitably fix the packing to the main pipe or the tubularportion and the insertion member and sealing is thus made.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1(A) and 1(B) are an explanatory view showing step-wise theassembly state in an embodiment of the present invention;

FIG. 2(A) is a side view and a sectional view of a packing used in thepresent invention

FIG. 2(B) is a plan view of the packing shown in FIG. 2(A);

FIG. 2(C) is a bottom view of the packing shown in FIG. 2(A);

FIG. 3 is an explanatory view of a winding operation of the packing toan insertion member;

FIG. 4 is a partial sectional view of the insertion member under thewound state;

FIG. 5 is a sectional view showing the assembly state of a mechanism ofthe present invention;

FIG. 6 is an edge view and a side view of a wedge-shaped nut in anotherembodiment of the present invention;

FIG. 7 is a sectional view showing the assembly state between a mainpipe or a tubular member and a clamping ring; and

FIGS. 8 through 11 are sectional views of conventional joint mechanism,respectively.

In these drawings, reference numeral 1 represents a main pipe; 1a is anew pipe or a tubular portion for equipment or the like; 2 is a clampingring; 2a is its male screw; 3 is a clamping ring; 4 is a nut member; 4ais its female screw; 5 is an insertion member; 6 is a packing; 6a is itsgroove portion; 7 is a seal tape; 8 is a wedge-shaped nut; 8a is itsfemale screw; 8b is its male screw; and 9 is its notch portion.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will be described in further detail with referenceto the accompanying drawings.

As shown in FIG. 1, the main pipes 1 and 1 or the main pipe 1 and atubular portion 1a which is inserted anew are connected to each other byuse of the first clamping ring 2 having the male screw 2a formedthereon, the second clamping ring 3 engaging with the nut member 4having the female screw 4a which meshes with the male screw 2a andmoreover, the insertion member 5 which is to be inserted between themain pipes 1 and 1 or between the main pipe 1 and a tubular portionincluding the end portion of equipment such as a valve inserted anew andwhich has an outer diameter greater than that of the pipes 1, 1 or thatof the tubular member 1a and, as shown in FIGS. 2 and 3, by use of apacking 6 equipped with a groove portion 6a for accommodating theinsertion member 5 at its intermediate portion. Furthermore, seal tape 7or the like is also used, whenever necessary, and the members describedabove are clamped as shown in FIG. 5.

Namely, while the first and second clamping rings 2, 3 and the nutmember 4 are fitted to the outside of the pipes 1, 1 or the pipe 1 andthe tubular portion 1a as shown in FIG. 1(A), the insertion member 5 ispositioned between the end surfaces of the pipes 1 and 1 or between theend surfaces of the pipe 1 and tubular portion 1a as shown in FIG. 1(B).A ring-like member having an inner hole 5a is used for the insertionmembers 5 when the fluid is caused to flow after the connection iscompleted but a blank sheet-like member is used when the passage of thefluid is stopped after the connection. (Such a case occurs frequently onthe site.)

After the insertion member 5 is assembled in the manner described above,the packing 6 such as the one shown in FIG. 2 is then wound on theinsertion member 5 and between the end portions of the pipes 1, 1 (or 1,1a, which will be hereinafter referred to merely as "1, 1"). A planepacking or a ring packing is used as the packing 6. In the case of theplane packing, it is prepared in the form of a belt having a grooveportion 6a at its middle portion. The end of this belt-like packing iscut in a predetermined length and in a taper form as shown in FIGS. 2(A)and 3 and a peripheral side of the insertion member 5 having a greaterdiameter than that of the pipes 1, 1 as described above is fitted andset to the groove portion 6a of the packing 6. Where the leak of thefluid is likely to occur from the tapered superposed portion of theplane packing, the packing in the ring-like form, or the ring packing,is employed, and its groove portion is fitted from the side portion ofthe insertion member 5. The seal tape 7 is further wound onto the outersurface of the packing 6 as shown in FIG. 4, whenever necessary. Undersuch a state, the female screw 4a of the nut member 4 is meshed with themale screw 2a of the first clamping ring 2 and both clamping rings 2 and3 are fastened by the nut member 4. In other words the outer surface ofthe packing 6 or seal tape 7 is compressed on the joint surfaces of bothclamping rings 2, 3 and connection is thus completed. The joint surfaceof both clamping rings 2, 3 is rounded appropriately so as to facilitateclamping and to attain stable fixing.

Although the joint mechanism of the present invention described abovepermits fundamentally extension and contraction of the main pipe to someextents, it tends to be insufficient to a tensile force. Therefore, whenthe joint mechanism is employed under the condition where the tensileforce acts, a flexible tube (pipe) such as of a bellows type is used oralternatively, the wedge-shaped nut 8 such as shown in FIG. 6 is used.The flexible tube can be fitted to any known joint by shaping it as afitting pipe. The wedge-shaped nut 8 is equipped with the female screw8a in its inner hole into which the main pipe 1 or the tubular portion1a is fitted and with the male screw 8b on its outer peripheral tapersurface. Moreover, the notch portion 9 is formed at part of its outerperiphery. The clamping ring 2 or 3 which mates with such a wedge-shapednut 8 is equipped with the tapered female screw 2b or 3b engaging withthe male screw 8b described above.

When the male screw 8b of the wedge-shaped nut 8 is meshed with thefemale screw 2b or 3b under the state where the joint mechanism of thepresent invention described above is set to a predetermined position,the wedge-shaped nut 8 itself is contracted within the range of itsnotch portion 9 and consequently, its female screw 8a comes into contactwith the outer peripheral surface of the main pipe 1 or the tubularportion 1a and connects it fixedly.

In the present invention described above, when the joint mechanism isemployed by cutting part of the main pipe 1 and using a new pipe as thetubular member 1 in the line of the main pipe 1 or when the equipmentsuch as a valve or a branch pipe is disposed in the line of the mainpipe 1, a pair of joint mechanisms of the present invention areassembled at both ends of the new pipe or between the end portions ofthe tubular portion 1a and the main pipe 1 on both sides of theequipment but the joint mechanism may be only one when the insertionmember 5 as the blind cover is disposed in the main pipe 1 so as to stopflow of the fluid or when the insertion member 5 having the passage holeis disposed only for the hole made in part of the main pipe 1 or for anyother hole portion.

Painting or planting for corrosion proofing is applied to the members ofthe joint mechanism of the present invention that are made of a steelmaterial or other metals and painting or a member for preventingelectrolytic corrosion is interposed at necessary portions. A suitablematerial such as a rubber material or resin material can be selected forthe packing 6 described above in accordance with the kind of the fluidflowing through the pipe, its pressure conditions, and so forth. Typicalexamples of the materials are ethylene-propylene rubber,ethylene-propylene sponge, nitrilebutyl rubber (NBR), silicon rubber,Viton and Kalrez.

Industrial Applicability

In accordance with the present invention described above, connection canbe made by merely interposing the insertion member between the endsurfaces of the main pipe and the new pipe to be connected or betweenthe end surfaces of the main pipe and the tubular portion of theequipment or branch pipe and then engaging the nut member anchored toone of the clamping rings with the other of the clamping rings.Accordingly, the intended work can be executed appropriately bydestroying the wall surface or the soil layer of only the work portionin the line of the main pipe but does not need destruction andexcavation for a broad range in the longitudinal direction of the lineof the main pipe for the purpose of welding or screw-threading. Thus theoverall quantity of execution works inclusive of the repair work afterconnection can be reduced remarkably and the execution works as well asthe connection work can be carried out easily and smoothly. Accordingly,the present invention can conduct the connection works extremelyadvantageously in all the aspects of the execution time, labor and cost.

We claim:
 1. A pipe joint mechanism for coupling opposing pipe sectionscomprising:an insertion member having a uniform width selected tosubstantially correspond to a distance between the opposing pipesections and an outer diameter greater than the outer diameter of theopposing pipe sections, said insertion member being positioned betweenthe opposing pipe sections; means for wrapping a packing member aroundthe circumference of said insertion member and spanning said insertionmember and at least a portion of the opposing pipe sections; a firstclamping ring slidable over an exposed end of a first opposing pipesection, said first clamping ring having an inner inclined surface andincluding male threads formed around an exterior circumference thereof;a second clamping ring slidable over an exposed end of a second opposingpipe section, said second clamping ring having an inner inclined surfaceand including a notch formed around an exterior circumference thereof; anut member around said second clamping ring, said nut member including anotch for engagement with the notch of said second clamping ring andincluding female threads formed on an inner periphery thereof forthreadable connection with said male threads, wherein the connection ofsaid nut member with said first connecting ring presses the innerinclined surfaces of said first and second connecting rings against saidpacking member and an outer circumference of said insertion memberthereby providing a fluid-tight seal between said opposing pipesections.
 2. The pipe joint mechanism according to claim 1, furtherincluding a seal tape wrapped around and overlapping said packing memberand the opposing pipe sections for increasing the effectiveness of thefluid-tight seal.
 3. The pipe joint mechanism according to claim 1,wherein said insertion member includes an annular aperture correspondingin diameter to an inner diameter of said opposing pipe sections forallowing passage of fluid therebetween upon coupling of the opposingpipe sections.
 4. The pipe joint mechanism according to claim 1, whereinsaid packing member is formed of a resilient material of a semicircleshape in cross section and including an inner groove corresponding incross section to the outer diameter of said insertion member, wherebythe connection presses the inner groove into a secured engagement withthe outer periphery of said insertion member and distends the distalends of the packing member into a secured engagement with the opposingpipe sections.
 5. The pipe joint mechanism according to claim 4, whereinsaid resilient material is one of ethylene-propylene rubber,ethylene-propylene sponge, nitrilebutyl rubber and silicon rubber. 6.The pipe joint mechanism according to claim 4, wherein said resilientmaterial is a rubber material.
 7. The pipe joint mechanism according toclaim 4, wherein said resilient material is a resin material.
 8. Thepipe joint mechanism according to claim 1, wherein said insertion memberis a solid member to prevent passage of fluid between opposing pipesections upon coupling thereof.